Structure and formation method of chip package with redistribution layers

ABSTRACT

Structures and formation methods of a chip package are provided. The chip package includes a semiconductor die and a protective layer surrounding the semiconductor die. The chip package also includes an interface between the semiconductor die and the protective layer. The chip package further includes a conductive layer over the protective layer and the semiconductor die, and the conductive layer has a first portion and a second portion. The first portion is closer to an inner portion of the semiconductor die than the second portion. The first portion is in direct contact with the second portion. The second portion extends across the interface, and the second portion has a line width greater than that of the first portion.

BACKGROUND

The semiconductor integrated circuit (IC) industry has experienced rapidgrowth. Continuing advances in semiconductor manufacturing processeshave resulted in semiconductor devices with finer features and/or higherdegrees of integration. Functional density (i.e., the number ofinterconnected devices per chip area) has generally increased whilefeature size (i.e., the smallest component that can be created using afabrication process) has decreased. This scaling-down process generallyprovides benefits by increasing production efficiency and loweringassociated costs.

A chip package not only provides protection for semiconductor devicesfrom environmental contaminants, but also provides a connectioninterface for the semiconductor devices packaged therein. Smallerpackage structures, which utilize less area or are lower in height, havebeen developed to package the semiconductor devices.

New packaging technologies have been developed to further improve thedensity and functionalities of semiconductor dies. These relatively newtypes of packaging technologies for semiconductor dies facemanufacturing challenges.

BRIEF DESCRIPTION OF THE DRAWINGS

Aspects of the present disclosure are best understood from the followingdetailed description when read with the accompanying figures. It shouldbe noted that, in accordance with the standard practice in the industry,various features are not drawn to scale. In fact, the dimensions of thevarious features may be arbitrarily increased or reduced for clarity ofdiscussion.

FIGS. 1A-1J are cross-sectional views of various stages of a process forforming a chip package, in accordance with some embodiments.

FIG. 2 is a partial top view of an intermediate stage of a process forforming a chip package, in accordance with some embodiments.

FIG. 3 is a partial top view of an intermediate stage of a process forforming a chip package, in accordance with some embodiments.

FIG. 4A is a fragmentary top view of a conductive layer in a chippackage, in accordance with some embodiments.

FIG. 4B is a fragmentary top view of a conductive layer in a chippackage, in accordance with some embodiments.

DETAILED DESCRIPTION

The following disclosure provides many different embodiments, orexamples, for implementing different features of the provided subjectmatter. Specific examples of components and arrangements are describedbelow to simplify the present disclosure. These are, of course, merelyexamples and are not intended to be limiting. For example, the formationof a first feature over or on a second feature in the description thatfollows may include embodiments in which the first and second featuresare formed in direct contact, and may also include embodiments in whichadditional features may be formed between the first and second features,such that the first and second features may not be in direct contact. Inaddition, the present disclosure may repeat reference numerals and/orletters in the various examples. This repetition is for the purpose ofsimplicity and clarity and does not in itself dictate a relationshipbetween the various embodiments and/or configurations discussed.

Further, spatially relative terms, such as “beneath,” “below,” “lower,”“above,” “upper” and the like, may be used herein for ease ofdescription to describe one element or feature's relationship to anotherelement(s) or feature(s) as illustrated in the figures. The spatiallyrelative terms are intended to encompass different orientations of thedevice in use or operation in addition to the orientation depicted inthe figures. The apparatus may be otherwise oriented (rotated 90 degreesor at other orientations) and the spatially relative descriptors usedherein may likewise be interpreted accordingly.

Embodiments of the disclosure may be applied in 3D packaging or 3D ICdevices. Other features and processes may also be included. For example,testing structures may be included to aid in the verification testing ofthe 3D packaging or 3DIC devices. The testing structures may include,for example, test pads formed in a redistribution layer or on asubstrate that allows the testing of the 3D packaging or 3DIC, the useof probes and/or probe cards, and the like. The verification testing maybe performed on intermediate structures as well as the final structure.Additionally, the structures and methods disclosed herein may be used inconjunction with testing methodologies that incorporate intermediateverification of known good dies to increase the yield and decreasecosts.

Some embodiments of the disclosure are described. Additional operationscan be provided before, during, and/or after the stages described inthese embodiments. Some of the stages that are described can be replacedor eliminated for different embodiments. Additional features can beadded to the semiconductor device structure. Some of the featuresdescribed below can be replaced or eliminated for different embodiments.Although some embodiments are discussed with operations performed in aparticular order, these operations may be performed in another logicalorder.

FIGS. 1A-1J are cross-sectional views of various stages of a process forforming a chip package, in accordance with some embodiments. As shown inFIG. 1A, an adhesive layer 102 and a base layer 104 are deposited orlaminated over a carrier substrate 100, in accordance with someembodiments.

In some embodiments, the carrier substrate 100 is used as a temporarysupport substrate. The carrier substrate 100 may be made of asemiconductor material, ceramic material, polymer material, metalmaterial, another suitable material, or a combination thereof. In someembodiments, the carrier substrate 100 is a glass substrate. In someother embodiments, the carrier substrate 100 is a semiconductorsubstrate, such as a silicon wafer.

The adhesive layer 102 may be made of glue, or may be a laminationmaterial, such as a foil. In some embodiments, the adhesive layer 102 isphotosensitive and is easily detached from the carrier substrate 100 bylight irradiation. For example, shining ultra-violet (UV) light,infrared light, or laser light on the carrier substrate 100 is used todetach the adhesive layer 102. In some embodiments, the adhesive layer102 is a light-to-heat-conversion (LTHC) coating. In some otherembodiments, the adhesive layer 102 is heat-sensitive. The adhesivelayer 102 may be detached using a thermal operation.

In some embodiments, the base layer 104 is a polymer layer or apolymer-containing layer. The base layer 104 may be a polybenzoxazole(PBO) layer, a polyimide (PI) layer, a solder resist (SR) layer, anAjinomoto buildup film (ABF), a die attach film (DAF), another suitablelayer, or a combination thereof. In some embodiments, the base layer 104includes multiple sub-layers.

Many variations and/or modifications can be made to embodiments of thedisclosure. In some other embodiments, the base layer 104 is not formed.

Afterwards, a seed layer 106 is deposited over the base layer 104, asshown in FIG. 1A in accordance with some embodiments. In someembodiments, the seed layer 106 is made of a metal material. The metalmaterial may be made of or include titanium (Ti), Ti alloy, copper (Cu),Cu alloy, another suitable material, or a combination thereof. In someother embodiments, the seed layer 106 includes multiple sub-layers.

In some embodiments, the seed layer 106 is deposited using a physicalvapor deposition (PVD) process such as a sputtering process, a chemicalvapor deposition (CVD) process, a spin-on process, another applicableprocess, or a combination thereof.

Many variations and/or modifications can be made to embodiments of thedisclosure. In some other embodiments, the seed layer 106 is not formed.

As shown in FIG. 1B, conductive structures including conductivestructures 112A, 112B, 112C, and 112D are formed, in accordance withsome embodiments. In some embodiments, the conductive structures 112A,112B, 112C, and 112D include conductive pillars. In some embodiments,each of the conductive structures 112A, 112B, 112C, and 112D has alinear sidewall. In some embodiments, the linear sidewall issubstantially perpendicular to a main surface of the base layer 104.

In some embodiments, a mask layer (not shown) is formed over the seedlayer 106 to assist in the formation of the conductive structures112A-112D. The mask layer has multiple openings that expose portions ofthe seed layer 106. The openings of the mask layer define positionswhere the conductive structures will be formed. In some embodiments, themask layer is made of a photoresist material.

In some embodiments, the conductive structures 112A-112D are made of orinclude a metal material. The metal material may include Cu, Ti, gold(Au), cobalt (Co), aluminum (Al), tungsten (W), another suitablematerial, or a combination thereof. In some embodiments, the conductivestructures 112A-112D are made of or include a solder material. Thesolder material may include tin (Sn) and other metal elements. In someother embodiments, the conductive structures 112A, 112B, 112C, and 112Dare made of a metal material that does not include Sn.

In some embodiments, the conductive structures 112A, 112B, 112C, and112D are formed using a plating process utilizing the seed layer 106.The plating process may include an electroplating process, anelectroless plating process, another applicable process, or acombination thereof.

However, many variations and/or modifications can be made to embodimentsof the disclosure. In some other embodiments, the conductive structures112A, 112B, 112C, and 112D are formed using a chemical vapor deposition(CVD) process, a physical vapor deposition (PVD) process, a spin-onprocess, another applicable process, or a combination thereof.

Afterwards, the mask layer is removed, and the portions of the seedlayer 106 that are not covered by the conductive structures 112A-112Dare removed, as shown in FIG. 1B in accordance with some embodiments. Anetching process may be used to partially remove the seed layer 106. Theconductive structures 112A-112D may function as an etching mask duringthe etching of the seed layer 106.

Many variations and/or modifications can be made to embodiments of thedisclosure. In some other embodiments, the seed layer 106 and/or theconductive structures 112A-112D are not formed.

As shown in FIG. 1C, semiconductor dies including semiconductor dies122A and 122B are attached over the carrier substrate 100, in accordancewith some embodiments. In some embodiments, back sides of thesemiconductor dies 122A and 122B face the base layer 104 with frontsides of the semiconductor dies 122A and 122B facing away therefrom. Anadhesive film 120 may be used to affix the semiconductor dies 122A and122B to the base layer 104. The adhesive film 120 may include a dieattach film (DAF), a glue, or another suitable film.

Each of the semiconductor dies 122A and 122B may include a semiconductorsubstrate 114, a dielectric structure 116, and conductive elements 118located at the front side thereof. The dielectric structure 116 mayinclude multiple dielectric layers (not shown). The conductive elements118 may be conductive pads, portions of conductive lines, or the like.In some embodiments, various device elements are formed in and/or on thesemiconductor substrate 114.

Examples of the various device elements include transistors (e.g., metaloxide semiconductor field effect transistors (MO SFET), complementarymetal oxide semiconductor (CMOS) transistors, bipolar junctiontransistors (BJT), high-voltage transistors, high-frequency transistors,p-channel and/or n-channel field effect transistors (PFETs/NFETs),etc.), diodes, or other suitable elements.

The device elements are interconnected to form integrated circuitdevices through conductive features formed in the dielectric structure116. The dielectric structure 116 may include multiple sub-layers. Theconductive features may include multiple conductive lines, conductivecontacts, and conductive vias. In some embodiments, electricalconnections between the conductive elements 118 and the device elementsare formed through the conductive features formed in the dielectricstructure 116. In some embodiments, the conductive elements 118 aremetal pads which may be made of aluminum or another suitable material.

The integrated circuit devices include logic devices, memory devices(e.g., static random access memories, SRAMs), radio frequency (RF)devices, input/output (I/O) devices, system-on-chip (SoC) devices, otherapplicable types of devices, or a combination thereof. In someembodiments, the semiconductor die 122A or 122B is a system-on-chip(SoC) chip that includes multiple functions.

In some other embodiments, the conductive elements 118 are conductivepillars that are electrically connected to conductive pads or conductivelines thereunder. A passivation layer such as a PBO layer or anothersuitable layer may be used to surround the conductive pillars. In someembodiments, the conductive pillars are copper pillars.

As shown in FIG. 1D, a protective layer 124 is formed over the carriersubstrate 100 to surround the conductive structures 112A-112D and thesemiconductor dies 122A and 122B, in accordance with some embodiments.In some embodiments, the protective layer 124 covers the sidewalls ofthe conductive structures 112A-112D and the semiconductor dies 122A and122B. In some embodiments, the protective layer 124 is in direct contactwith the semiconductor dies 122A and 122B. In some embodiments, aninterface 125 is formed between the protective layer 124 and thesemiconductor die 122A.

In some embodiments, the protective layer 124 includes a polymermaterial. In some embodiments, the protective layer 124 includes amolding compound material. The molding compound material may include aresin (such as an epoxy-based resin) with fillers dispersed therein. Themolding compound material may include another suitable resin.

In some embodiments, the protective layer 124 is formed by injecting amolding compound material over the carrier substrate 100. In someembodiments, a transfer mold is used to assist in the formation of theprotective layer 124. After or during the injecting of the moldingcompound material, the molding compound material does not cover the topsurfaces of the conductive structures 112A-112D and/or the semiconductordies 122A and 122B.

In some embodiments, a liquid molding compound material is disposed overthe carrier substrate 100 to encapsulate or partially cover theconductive structures 112A-112D and the semiconductor dies 122A and122B. The liquid molding compound material may be made of or includeliquid state epoxy resin, liquid state epoxy acrylate, liquid stateepoxy resin with filler, liquid state epoxy acrylate with filler, one ormore other suitable liquid state materials, or a combination thereof. Insome embodiments, a thermal process is then applied to harden the liquidmolding compound material and to transform it into the protective layer124. In some embodiments, the thermal process is performed at atemperature in a range from about 200 degrees C. to about 250 degrees C.The operation time of the thermal process may be in a range from about0.5 hour to about 3 hours.

In some other embodiments, a liquid molding compound material isdisposed over the carrier substrate 100 to cover the conductivestructures 112A-112D and the semiconductor dies 122A and 122B.Afterwards, a thermal process is then applied to harden the liquidmolding compound material and to transform it into the protective layer124. A thinning process is then used to thin down the protective layer124 until the conductive structures 112A-112D and/or the conductiveelements 118 are exposed.

As shown in FIG. 1E, a dielectric layer 128 a is formed over theprotective layer 124, the conductive structures 112A-112D, and thesemiconductor dies 122A and 122B, in accordance with some embodiments.In some embodiments, the dielectric layer 128 a is made of or includesone or more polymer materials or other suitable materials. Thedielectric layer 128 a may be made of or include polybenzoxazole (PBO),polyimide (PI), silicon oxide, another suitable material, or acombination thereof. In some embodiments, the dielectric layer 128 a isformed using a spin coating process, a spray coating process, a CVDprocess, another applicable process, or a combination thereof.

As shown in FIG. 1E, the dielectric layer 128 a is patterned to formmultiple openings 129, in accordance with some embodiments. In someembodiments, some of the openings 129 correspondingly expose theconductive structures 112A-112D. In some embodiments, some of theopenings 129 correspondingly expose the conductive elements 118 of thesemiconductor dies 122A and 112B. In some embodiments, the openings 129are formed using a photolithography process, a laser drilling process,an etching process, an energy beam writing process, another applicableprocess, or a combination thereof.

As shown in FIG. 1F, multiple conductive layers (or redistributionlayers) including conductive layers 130 a are formed over the dielectriclayer 128 a, in accordance with some embodiments. In some embodiments,the conductive layers 130 a are in direct contact with the dielectriclayer 128 a. In some embodiments, the dielectric layer 128 a is indirect contact with the protective layer. In some embodiments, theconductive layers 130 a are separated from the protective layer 124 bythe dielectric layer 128 a.

In some embodiments, each of the conductive layers 130 a fills thecorresponding opening 129. In some embodiments, In some embodiments,each conductive structure 112A to 112D is electrically connected to acorresponding one of the conductive layers 130 a through a correspondingone of the openings 129. In some embodiments, each conductive feature118 (such as a conductive pad) of the semiconductor die 122A iselectrically connected to a corresponding one of the conductive layers130 a through a corresponding one of the openings 129. In someembodiments, the conductive structure 112A is electrically connected toone of the conductive features 118 of the semiconductor die 122A throughthe corresponding one of the conductive layers 130 a.

In some embodiments, the conductive layers 130 a are made of or includea metal material. The metal material may include copper, aluminum,titanium, cobalt, gold, platinum, another suitable material, or acombination thereof. In some embodiments, the conductive layers 130 aare formed using an electroplating process, an electroless platingprocess, a PVD process, a CVD process, another applicable process, or acombination thereof. A pattern mask layer and an etching process may beused to pattern a conductive material layer such that the conductivelayers 130 a with desired patterns are formed.

FIG. 2 is a partial top view of an intermediate stage of a process forforming a chip package, in accordance with some embodiments. In someembodiments, FIG. 2 is a top view of a portion of the structure shown inFIG. 1F. FIG. 2 shows the relationship between one of the conductivelayers 130 a and the interface 125 between the semiconductor die 122Aand the protective layer 124. For clarity, the dielectric layer 128 abetween the conductive layer 130 a and the semiconductor die 122A (orthe protective layer 124) is not shown in FIG. 2.

In some embodiments, the conductive layer 130 a has a first portion 131Aand a second portion 131B, as shown in FIG. 2. In some embodiments, thefirst portion 131A is closer to an inner portion 121 i of thesemiconductor die 122A than the second portion 131B. In someembodiments, the second portion 131B has a greater line width than thefirst portion 131A. In some embodiments, the second portion 131B has agreater stress resistance than the first portion 131A. The secondportion 131B may have a higher mechanical strength to sustain stress(such as thermal stress). The stress resistance (or the mechanicalstrength) of the first portion 131A and the second portion 131B may bemeasured by, for instance, thermal cycling test, bend test or othersuitable techniques in the art.

In some embodiments, the first portion 131A is in direct contact withthe second portion 131B. In some embodiments, the conductive layer 130 ais electrically connected to one of the conductive elements 118, asshown in FIGS. 1F and 2. In some embodiments, the first portion 131A isbetween the second portion 131B and the conductive element 118. In someembodiments, the conductive layer 130 a has a portion filling one of theopenings 129. The portion filling the opening may form a conductive via.The first portion 131A is electrically connected to the conductiveelement 118 of the semiconductor die 122A through the conductive via.

In some embodiments, the second portion 131B extends across theinterface 125 between the semiconductor die 122A and the protectivelayer 124. The first portion 131A does not extend across the interface125. In these cases, the second portion 131B may also be referred to asan interface-crossing section. In some embodiments, the sizes and/orshapes of the first portion 131A and the second portion 131B aredifferent from each other. In some embodiments, the first portion 131Aand the second portion 131B are patterned from the same conductivelayer. In some embodiments, the first portion 131A and the secondportion 131B are made of the same material.

In some embodiments, the semiconductor die 122A and the protective layer124 have different thermal expansion coefficients. As a result, highthermal stress may be generated near the interface 125 between thesemiconductor die 122A and the protective layer 124 during subsequentformation processes and/or operation of the final product. Therefore,the second portion 131B of the conductive layer 130 a that extendsacross the interface 125 may suffer higher thermal stress than the firstportion 131A.

In some embodiments, because the second portion 131B is wider than thefirst portion 131A, the second portion 131B has a higher strength (orhigher stress resistance) to sustain the higher thermal stress. Theconductive layer 130 a is therefore prevented from being damaged orbroken near the interface 125. The quality and reliability of theconductive layer 130 a are significantly improved.

As shown in FIG. 2, the second portion 131B has a line width W₂, and thefirst portion 131A has a line width W₁. The width W₂ is greater than thewidth W₁. In some embodiments, the line width W₁ is the average linewidth of the first portion 131A. In some embodiments, the line width W₂is the average line width of the second portion 131B. In someembodiments, the second portion 131B has a substantially uniform linewidth.

In some embodiments, the line width ratio (W₁/W₂) of the first portion131A to the second portion 131B is in a range from about 0.2 to about0.8. However, embodiments of the disclosure are not limited thereto. Theline width ratio (W₁/W₂) may be in a different range. In some otherembodiments, the line width ratio (W₁/W₂) is in a range from about 0.3to about 0.7. In some cases, if the line width ratio (W₁/W₂) is greaterthan about 0.8 (or 0.7), the line width W₂ might not be wide enough tosustain the high thermal stress. In some other cases, if the line widthratio (W₁/W₂) is lower than about 0.2 (or 0.3), the line width W₂ mightbe too wide, leading to short circuiting between two neighboringconductive layers. In some embodiments, the line width W₂ of the secondportion 131B is in a range from about 10 μm to about 30 μm. However,embodiments of the disclosure are not limited thereto. In some otherembodiments, the line width W₂ is in a range from about 1 μm to about 50μm.

As shown in FIG. 2, the semiconductor die 122A has a peripheral portion121 p and the inner portion 121 i. The peripheral portion 121 psurrounds the inner portion 121 i. As shown in FIG. 2, the peripheralportion 121 p of the semiconductor die 122A, the interface 125, and aportion of the protective layer 124 adjacent to the interface 125together form a die boundary region R (i.e., the area between the dashedlines in FIG. 2). The die boundary region R surrounds the inner portion121 i of the semiconductor die 122A.

The die boundary region R may represent the positions where theconductive layer or conductive line may suffer higher thermal stress. Insome embodiments, a portion of the second portion 131B of the conductivelayer 130 a is positioned directly above the die boundary region R. Insome embodiments, the entire second portion 131B is positioned directlyabove the die boundary region R. For example, the second portion 131B isformed on the portion of the dielectric layer 128 a that is directly onthe die boundary region R. In some embodiments, the first portion 131Aof the conductive layer 130 a is not positioned directly above the dieboundary region R.

Because the portion of the conductive layer 130 a that is directly abovethe die boundary region R has a greater line width, the risk of linebreakage of the conductive layer 130 a due to high thermal stress issignificantly reduced. In some embodiments, the segment or portion ofeach of the conductive layers 130 extending across the interface 125 iswider than the first portion 131A. In some embodiments, there is noconductive line having a segment (or a portion) extending across theinterface 125, being directly on the dielectric layer 128 a, and beingas wide as or narrower than the first portion 131A of the conductivelayer 130 a. In some embodiments, there is no conductive line thatextends across the interface 125, that is directly on the dielectriclayer 128 a, and that has an interface-crossing section as wide as ornarrower than the first portion 131A of the conductive layer 130 a.Therefore, the risk of line breakage of the conductive layers 130 a issignificantly reduced.

As shown in FIG. 2, an inner edge of the die boundary region R isseparated from the interface 125 by a first distance a₁. For example,the distance a₁ is the minimum distance between the interface 125 andthe inner edge of the die boundary region R. An outer edge of the dieboundary region R is separated from the interface 125 by a seconddistance a₂. For example, the distance a₂ is the minimum distancebetween the interface 125 and the outer edge of the die boundary regionR. In some embodiments, the distance a₁ is substantially equal to thedistance a₂.

In some embodiments, the distance a₁ is in a range from about 25 μm toabout 50 μm. In some other embodiments, the distance a₁ is in a rangefrom about 10 μm to about 70 μm. As shown in FIG. 1F, the semiconductordie 122A has a width b. In some embodiments, the ratio (a₁/b) of thefirst distance a₁ to the width b of the semiconductor die 122A is in arange from about 0.025 to about 0.1. However, embodiments of thedisclosure are not limited thereto. In some other embodiments, the ratio(a₁/b) is in a range from about 0.01 to about 0.2.

As shown in FIG. 2, the second portion 131B has a first part 131B₁ and asecond part 131B₂. The first part 131B₁ is directly above thesemiconductor die 122A. The second part 131B₂ is directly above theprotective layer 124. In some embodiments, the length of the second part131B₂ is equal to that of the first part 131B₁. In some otherembodiments, the length of the second part 131B₂ is greater than that ofthe first part 131B₁.

In some embodiments, the conductive layer 130 a has a third portion131C, as shown in FIG. 2. The second portion 131B is between the thirdportion 131C and the first portion 131A. The third portion 131C does notextend across the interface 125. In some embodiments, the third portion131C is positioned outside of the die boundary region R. The thirdportion 131C has a line width W₃. In some embodiments, the third portion131C has a substantially uniform line width. In some embodiments, theline width W₃ is an average line width of the third portion 131C. Insome embodiments, the line width W₂ is greater than the line width W₃.In some other embodiments, the line widths W₂ and W₃ are the same. Insome other embodiments, the line width W₃ is greater than the line widthW₂.

In some embodiments, the line width of the first portion 131A adjacentto the second portion 131B becomes wider along a direction towards thesecond portion 131B. For example, the line width of the first portionincreases from the width W₁ to be the width W₄. The width W₄ maygradually become greater along the direction towards the second portion131B.

Many variations and/or modifications can be made to embodiments of thedisclosure. FIGS. 4A and 4B are fragmentary top views of a conductivelayer in a chip package, in accordance with some embodiments. In someembodiments, the second portion 131B has rounded corner portions C, asshown in FIG. 4A. In some other embodiments, an edge portion C′ of thesecond portion 131B adjacent to the first portion 131A is rounded, asshown in FIG. 4B.

As shown in FIG. 2, at least one part of the interface 125 extends alonga first elongation direction d1 observed from a top view of thesemiconductor die 122A and the protective layer 124. The second portion131B of the conductive layer 130 a extending across the part of theinterface 125 extends along a second elongation direction d2. In someembodiments, the first elongation direction d1 is substantiallyperpendicular to the second elongation direction d2. In some otherembodiments, the first elongation direction d1 is not perpendicular tothe second elongation direction d2.

Many variations and/or modifications can be made to embodiments of thedisclosure. FIG. 3 is a partial top view of an intermediate stage of aprocess for forming a chip package, in accordance with some embodiments.In some embodiments, FIG. 3 is a top view of a portion of the structureshown in FIG. 1F. FIG. 3 shows the relationship between the conductivelayers 130 a (including conductive layers 130 a′) and the interface 125between the semiconductor die 122A and the protective layer 124. Forclarity, the dielectric layer 128 a between the conductive layer 130 aand the semiconductor die 122A (or the protective layer 124) is notshown in FIG. 3.

As shown in FIG. 3, one of the conductive layers such as the conductivelayer 130 a′ extends along an elongation direction d2′. Another part ofthe interface 125 may extend along an elongation direction d1′. In someembodiments, the elongation directions d1′ and d2′ are not perpendicularto each other.

In some embodiments, the conductive layer 130 a′ is electricallyconnected to one of the conductive elements 118 of the semiconductor die122A. However, embodiments of the disclosure are not limited thereto. Insome other embodiments, the conductive layer 130 a′ is not electricallyconnected to the conductive elements 118 of the semiconductor die 122A.

In some embodiments, there is one (or more) conductive layer 402 overthe dielectric layer 128 a. In some embodiments, the conductive layer402 does not extend across the interface 125. In some embodiments, theconductive layer 402 is directly on the dielectric layer 128 a. In someembodiments, the conductive layer 402 has a first segment 403 apositioned directly above the die boundary region R and a second segment403 b positioned outside of the die boundary region R. In someembodiments, the shortest distance a₃ between the segment 403 a and theinterface 125 is shorter than the shortest distance a₁ between the firstportion 131A of the conductive layer 130 a and the interface 125.

In some embodiments, the segment 403 a has a line width W₅. In someembodiments, the line width W₅ is less than the line width W₂ of thesecond portion 131B of the conductive layer 130 a. In some embodiments,the line width W₅ is equal to or less than the line width W₁ of thefirst portion 131A of the conductive layer 130 a.

Since the conductive layer 402 does not extend across the interface 125,the conductive layer 402 is prevented from thermal stress generated dueto the different thermal expansion between the semiconductor die 122Aand the protective layer 124. Therefore, in some embodiments, it is notnecessary for the segment 403 a directly above the die boundary region Rto have a greater line width.

Referring back to FIG. 1G, a dielectric layer 128 b is formed over thedielectric layer 128 a and the conductive layers 130 a, in accordancewith some embodiments. In some embodiments, the material and formationmethod of the dielectric layer 128 b is the same as or similar to thoseof the dielectric layer 128 a.

However, embodiments of the disclosure are not limited thereto. In someother embodiments, the dielectric layer 128 b is made of a differentdielectric material than the dielectric layer 128 a. In someembodiments, the dielectric layer 128 b is made of silicon oxide or thelike using a deposition process, such as a chemical vapor deposition(CVD) process.

Afterwards, multiple dielectric layers including a dielectric layer 128c and a passivation layer 132 and multiple conductive layers includingconductive layers 130 b and 130 c are formed, as shown in FIG. 1G inaccordance with some embodiments. The material and formation method ofthe conductive layers 130 b and 130 c may be similar to or the same asthose of the conductive layers 130 a. In some embodiments, conductivebumps 134 are formed. An under bump metallurgy (UBM) layer (not shown)may be formed between the conductive bumps 134 and the conductive layers130 c.

As shown in FIG. 1G, the conductive layers 130 b or 130 c also haveportions that extend across the interface 125. In some embodiments, theconductive layers 130 b or 130 c also have patterns similar to or thesame as those of the conductive layer 130 a. The portions of theconductive layers 130 b and/or 130 c that are directly above the dieboundary region R may be designed to be wider to sustain the thermalstress near the interface 125. Therefore, the quality and reliability ofthe conductive layers 130 b and 130 c are also improved.

Afterwards, the structure shown in FIG. 1G is placed upside down on acarrier tape 240, as shown in FIG. 1H in accordance with someembodiments. The carrier substrate 100 and adhesive layer 102 areremoved, as shown in FIG. 1H. The carrier substrate 100 and adhesivelayer 102 may be removed using a light irradiation operation, a thermaloperation, another applicable operation, or a combination thereof.

As shown in FIG. 1I, one or more elements 170 are stacked on or bondedonto the structure as shown in FIG. 1H. The element 170 may includeanother chip package, a semiconductor die, one or more passive devices,another suitable structure, or a combination thereof.

In some embodiments, multiple conductive bumps 142 are formed toestablish electrical connections between the element 170 and thestructure thereunder, in accordance with some embodiments. In someembodiments, the conductive bumps 142 are made of or include a soldermaterial. The solder material may include tin and other metal materials.In some embodiments, the conductive bumps 142 are made of or includecopper, gold, aluminum, titanium, cobalt, platinum, another suitablematerial, or a combination thereof.

However, embodiments of the disclosure are not limited thereto. In someother embodiments, the elements 170 and/or the conductive bumps 142 arenot formed or stacked.

Afterwards, a dicing process (or a cutting operation) is performed toseparate the structure as shown in FIG. 1I into multiple chip packages,as shown in FIG. 1J in accordance with some embodiments. As a result, achip package with a fan-out structure is formed. In some embodiments,the carrier tape 240 is removed after the dicing process.

Many variations and/or modifications can be made to embodiments of thedisclosure. In some embodiments, the element 170 is stacked before thedicing process. In some other embodiments, the element 170 is stackedafter the dicing process.

Many variations and/or modifications can be made to embodiments of thedisclosure. In some embodiments, the chip package include only one ofthe semiconductor dies such as the semiconductor die 122A. In some otherembodiments, the chip package includes two or more of the semiconductordies. For example, the chip package may include the semiconductor dies122A and 122B.

Embodiments of the disclosure form a chip package having a semiconductordie surrounded by a protective layer. One (or more) conductive layer isformed over the semiconductor die and the protective layer. Theconductive layer extends across the interface between the semiconductordie and the protective layer. The portion of the conductive layerdirectly above a die boundary region including the interface is designedto have a greater line width. The portion having the greater line widthmay have a higher strength to sustain thermal stress generated near theinterface between the semiconductor die and the protective layer.Accordingly, the quality and reliability of the conductive layer aresignificantly improved.

In accordance with some embodiments, a chip package is provided. Thechip package includes a semiconductor die and a protective layersurrounding the semiconductor die. The chip package also includes aninterface between the semiconductor die and the protective layer. Thechip package further includes a conductive layer over the protectivelayer and the semiconductor die, and the conductive layer has a firstportion and a second portion. The first portion is closer to an innerportion of the semiconductor die than the second portion. The firstportion is in direct contact with the second portion. The second portionextends across the interface, and the second portion has a line widthgreater than that of the first portion.

In accordance with some embodiments, a chip package is provided. Thechip package includes a semiconductor die and a protective layersurrounding the semiconductor die. The chip package also includes aninterface between the semiconductor die and the protective layer. Thechip package further includes a conductive layer over the protectivelayer and the semiconductor die, and the conductive layer has a firstportion and a second portion. The first portion is closer to an innerportion of the semiconductor die than the second portion. The secondportion extends across the interface, and the second portion is widerthan the first portion.

In accordance with some embodiments, a chip package is provided. Thechip package includes a semiconductor die and a protective layersurrounding the semiconductor die. The chip package also includes aninterface between the semiconductor die and the protective layer. Thechip package further includes a conductive layer over the protectivelayer and the semiconductor die, and the conductive layer has a firstportion and a second portion. The second portion extends across theinterface, and the second portion has a greater average line width thanthe first portion.

In accordance with some embodiments, a chip package is provided. Thechip package includes a semiconductor die and a protective layersurrounding the semiconductor die. The chip package also includes aninterface between the semiconductor die and the protective layer. Thechip package further includes a conductive line formed over theprotective layer and the semiconductor die and having aninterface-crossing section that extends across the interface and thathas an enlarged line width.

In accordance with some embodiments, a chip package is provided. Thechip package includes a semiconductor die and a protective layersurrounding the semiconductor die. The chip package also includes aninterface between the semiconductor die and the protective layer. Thechip package further includes a conductive layer over the protectivelayer and the semiconductor die. The conductive layer has a firstportion and a second portion, and the first portion is closer to aninner portion of the semiconductor die than the second portion. Thesecond portion extends across the interface, and the second portion hasa greater stress resistance than the first portion.

The foregoing outlines features of several embodiments so that thoseskilled in the art may better understand the aspects of the presentdisclosure. Those skilled in the art should appreciate that they mayreadily use the present disclosure as a basis for designing or modifyingother processes and structures for carrying out the same purposes and/orachieving the same advantages of the embodiments introduced herein.Those skilled in the art should also realize that such equivalentconstructions do not depart from the spirit and scope of the presentdisclosure, and that they may make various changes, substitutions, andalterations herein without departing from the spirit and scope of thepresent disclosure.

What is claimed is:
 1. A chip package, comprising: a semiconductor die;a protective layer surrounding the semiconductor die; an interfacebetween the semiconductor die and the protective layer; and a conductivelayer over the protective layer and the semiconductor die, wherein theconductive layer has a first portion and a second portion, the firstportion is closer to an inner portion of the semiconductor die than thesecond portion, the first portion is in direct contact with the secondportion, the second portion extends across the interface, and in a topview of the conductive layer, the second portion has a line widthgreater than that of the first portion.
 2. The chip package as claimedin claim 1, wherein in the top view of the conductive layer, the linewidth of the first portion adjacent to the second portion increasestowards the second portion.
 3. The chip package as claimed in claim 1,wherein: at least a part of the interface extends along a firstelongation direction observed from a top view of the semiconductor dieand the protective layer, the second portion extends along a secondelongation direction observed from the top view of the conductive layer,and the first elongation direction is substantially perpendicular to thesecond elongation direction.
 4. The chip package as claimed in claim 1,wherein: at least a part of the interface extends along a firstelongation direction observed from a top view of the semiconductor dieand the protective layer, the second portion extends along a secondelongation direction observed from the top view of the conductive layer,and the first elongation direction is not perpendicular to the secondelongation direction.
 5. The chip package as claimed in claim 1, whereinthe first portion and the second portion are made of a same material. 6.The chip package as claimed in claim 1, wherein: the interface, aperipheral portion of the semiconductor die, and a portion of theprotective layer adjacent to the interface together form a die boundaryregion surrounding the inner portion of the semiconductor die, at leasta part of the second portion is positioned within the die boundaryregion, the first portion is not positioned within the die boundaryregion, an inner edge of the die boundary region is separated from theinterface by a first distance, and a ratio of the first distance to awidth of the semiconductor die is in a range from about 0.025 to about0.1.
 7. The chip package as claimed in claim 1, wherein: the interface,a peripheral portion of the semiconductor die, and a portion of theprotective layer adjacent to the interface together form a die boundaryregion surrounding the inner portion of the semiconductor die, at leasta part of the second portion is positioned within the die boundaryregion, the first portion is not positioned within the die boundaryregion, an inner edge of the die boundary region is separated from theinterface by a first distance, an outer edge of the die boundary regionis separated from the interface by a second distance, and the firstdistance is equal to the second distance.
 8. The chip package as claimedin claim 7, further comprising: a dielectric layer over thesemiconductor die and the protection layer; and a second conductivelayer over the dielectric layer, wherein: the second conductive layerdoes not extend across the interface, the second conductive layer has asegment positioned within the die boundary region, and the segment ofthe second conductive layer has a line width less than the line width ofthe second portion of the conductive layer.
 9. The chip package asclaimed in claim 1, wherein: the semiconductor die has a conductiveelement, the conductive layer is electrically connected to theconductive element, and the first portion physically interconnects thesecond portion and the conductive element.
 10. The chip package asclaimed in claim 1, wherein: the conductive layer has a third portionconnected to the second portion, the second portion is between the firstportion and the third portion, the third portion does not extend acrossthe interface, and the second portion is wider than the third portion.11. The chip package as claimed in claim 1, further comprising adielectric layer over the semiconductor die and the protective layer,wherein the chip package comprises no conductive line that extendsacross the interface, that is directly on the dielectric layer, and thathas an interface-crossing section as wide as or narrower than the firstportion of the conductive layer.
 12. The chip package as claimed inclaim 1, further comprising: a dielectric layer over the semiconductordie and the protective layer; a second conductive layer over thedielectric layer, wherein: the second conductive layer has a segmentseparated from the interface by a first distance, the first portion isseparated from the interface by a second distance, the first distance isshorter than the second distance, the second conductive layer does notextend across the interface, and the segment of the second conductivelayer is as wide as or narrower than the first portion of the conductivelayer.
 13. The chip package as claimed in claim 1, wherein a line widthratio of the first portion to the second portion is in a range fromabout 0.2 to about 0.8.
 14. The chip package as claimed in claim 1,wherein the second portion has a substantially uniform line width in thetop view of the conductive layer.
 15. The chip package as claimed inclaim 1, wherein: the second portion has a first part and a second part,the first part is directly above the semiconductor die, the second partis directly above the protective layer, and the second part has a lengthequal to or greater than that of the first part.
 16. The chip package asclaimed in claim 1, further comprising a dielectric layer overlying thesemiconductor die and the protective layer, wherein: the protectivelayer is in direct contact with the dielectric layer, and the conductivelayer is in direct contact with the dielectric layer.
 17. The chippackage as claimed in claim 1, further comprising a redistributionstructure between the semiconductor die and the conductive layer.
 18. Achip package, comprising: a semiconductor die; a protective layersurrounding the semiconductor die; an interface between thesemiconductor die and the protective layer; and a conductive line formedover the protective layer and the semiconductor die and having aninterface-crossing section that extends across the interface and thathas an enlarged line width in a top view of the conductive line.
 19. Achip package, comprising: a semiconductor die; a protective layersurrounding the semiconductor die; an interface between thesemiconductor die and the protective layer; and a conductive layer overthe protective layer and the semiconductor die, wherein the conductivelayer has a first portion and a second portion, the first portion iscloser to an inner portion of the semiconductor die than the secondportion, the second portion extends across the interface, and the secondportion has a greater stress resistance than the first portion, and thesecond portion is wider than the first portion in a top view of theconductive layer.
 20. The chip package as claimed in claim 19, whereinin the top view of the conductive layer, a line width of the firstportion adjacent to the second portion continuously increases towardsthe second portion.